Liquid crystal display

ABSTRACT

According to one embodiment, an apparatus includes an array substrate including gate lines and auxiliary capacitance lines extending along a row, signal lines extending along a column, a semiconductor that intersects the gate line via an insulating layer and confronts the auxiliary capacitance line, a contact electrode for electrically connecting the semiconductor to the pixel electrode, a counter substrate, and a liquid crystal layer sandwiched between the substrates. In the pixels disposed side by side in a direction where the gate line extends, the positions of center of gravity of openings surrounded by the gate lines, the signal lines, the auxiliary capacitance line, and ends of the contact electrode are the same in a direction where the signal line extends.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2012-074671, filed Mar. 28, 2012, theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a liquid crystaldisplay.

BACKGROUND

A liquid crystal display apparatus includes a pair of substrates, aliquid crystal layer sandwiched between the pair of substrates, and adisplay region having plural display pixels.

Further, in a liquid crystal display apparatus, as a countermeasureagainst flicker, there is proposed executing an alternating electricfield drive by inverting the polarity of a liquid crystal applicationvoltage every other scan line or every scan line. As a polarityinversion drive system, there are proposed polarity inversion (lineinversion) executed every other scan line (row), polarity inversion(column inversion) executed every other signal line (column), dotinversion drive in which polarity is inverted both every other scan lineand every other signal line, and the like.

In contrast, as a method of reducing a signal voltage amplitude, thereis proposed a capacitively-coupled (CC) drive. In thecapacitively-coupled drive, a predetermined voltage is reached bysuperimposing an auxiliary capacitance signal to a pixel electrode viaan auxiliary capacitance. When the capacitively-coupled drive isemployed, the signal voltage amplitude can be made to approximately halfits original amplitude at the time, for example, the auxiliarycapacitance is made approximately the same as a pixel capacitance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view schematically illustrating an configuration example ofa liquid crystal display apparatus of an embodiment;

FIG. 2 is a view illustrating a configuration example of an auxiliarycapacitance of a pixel in a liquid crystal display apparatus employing a1H1V-CCDI drive method and an example of a drive waveform;

FIG. 3 is a view illustrating a configuration example of an auxiliarycapacitance of a pixel in a liquid crystal display apparatus employing a2H1V-CCDI drive method and an example of a drive waveform;

FIG. 4 is a view illustrating a configuration example of an auxiliarycapacitance of a pixel in a liquid crystal display apparatus employing a4H1V-CCDI drive method and an example of a drive waveform;

FIG. 5 is a view illustrating an example of a pixel layout of the liquidcrystal display apparatus of the first embodiment;

FIG. 6 is a view illustrating an example of a sectional structure of aliquid crystal display panel taken along line VI-VI in FIG. 5;

FIG. 7 is a view illustrating an example of a sectional structure of aliquid crystal display panel taken along line VII-VII in FIG. 5;

FIG. 8 is a view illustrating an example of a display pattern when amonotone display is executed in a liquid crystal display apparatusemploying a 2H1V-CCDI drive system;

FIG. 9 is a view illustrating an example of a display pattern when a 1Vstripe display is executed in the liquid crystal display apparatusemploying the 2H1V-CCDI drive system;

FIG. 10 is a view illustrating an example of a display pattern when adot-check display is executed in the liquid crystal display apparatusemploying the 2H1V-CCDI drive system;

FIG. 11 is a view illustrating an example of a pixel layout of a liquidcrystal display apparatus of a second embodiment;

FIG. 12 is a view illustrating an offset of center of gravity of anopening of a pixel as to respective display patterns in the liquidcrystal display apparatus employing the 1H1V-CCDI drive;

FIG. 13 is a view illustrating an offset of center of gravity of anopening of a pixel as to the respective display patterns in the liquidcrystal display apparatus employing the 2H1V-CCDI drive;

FIG. 14 is a view illustrating an offset of center of gravity of anopening of a pixel as to the respective display patterns in the liquidcrystal display apparatus employing the 4H1V-CCDI drive;

FIG. 15 is a view illustrating an offset of center of gravity of anopening of a pixel as to the respective display patterns in a liquidcrystal display apparatus employing a CC column inversion drive; and

FIG. 16 is a view illustrating other configuration example of anauxiliary capacitance of a pixel in the liquid crystal display apparatusemploying the 2H1V-CCDI drive method and other example of the drivewaveform.

DETAILED DESCRIPTION

In general, according to one embodiment, a liquid crystal displayapparatus comprises: An array substrate comprising a pixel electrodedisposed to each of display pixels disposed in a matrix state, a gateline and an auxiliary capacitance line extending along a row along whichthe pixel electrode is arranged, a signal line extending along a columnalong which the pixel electrode is arranged, a semiconductor layer thatintersects the gate line via an insulating layer and confronts theauxiliary capacitance line, a contact electrode interposed between thesemiconductor layer and the pixel electrode for electrically connectingthe semiconductor layer to the pixel electrode, and a drive circuit fordriving the gate line, the signal line, and the auxiliary capacitanceline; a counter substrate disposed in confrontation with the arraysubstrate; and a liquid crystal layer sandwiched between the arraysubstrate and the counter substrate. In the display pixels disposed sideby side in a direction where the gate line extends, the positions ofcenter of gravity of openings surrounded by the gate line, the signalline, the auxiliary capacitance line, and ends of the contact electrodeare the same in a direction where the signal line extends.

The liquid crystal display apparatus according to the embodiment will beexplained below in detail referring to drawings.

In the embodiment, a capacitively-coupled dot inversion (CCDI) drive isemployed as a drive method of the liquid crystal display apparatus. Theembodiment employs a capacitively-coupled dot inversion drive (nH1V-CCDIdrive) in which, in particular, n is set to an integer of 1 or more andpolarity is inverted every n scan lines and polarity is inverted everyother signal line in the CCDI drive. The capacitively-coupled (CC) driveobtains amplitude increase effect by applying a superimposed voltage bya capacitively-coupled coupling to a pixel potential after writing hasbeen executed from a signal line S to a pixel.

FIG. 1 is a view schematically illustrating a configuration example theliquid crystal display apparatus of the embodiment. Note that FIG. 1illustrates a configuration of a liquid crystal display apparatusemploying a 2H1V-CCDI drive system as an example.

The liquid crystal display apparatus according to the embodimentincludes a liquid crystal display panel LPN having a display unit DYPincluding plural display pixels PX, a backlight BL disposed toilluminate the display unit DYP of the liquid crystal display panel LPN,and a control circuit CTR for controlling the liquid crystal displaypanel LPN and backlight BL.

The liquid crystal display panel LPN has a pair of substrates, that is,an array substrate AR (FIG. 6 and FIG. 7) and a counter substrate CT(FIG. 6 and FIG. 7), and a liquid crystal layer LQ (FIG. 6 and FIG. 7)sandwiched between the array substrate AR and the counter substrate CT.

The liquid crystal display apparatus according to the embodiment is acolor display type liquid crystal display apparatus and the pluraldisplay pixels PX include plural color display pixels. The liquidcrystal display apparatus illustrated in FIG. 1 include red colordisplay pixels PXR for displaying red color, green display pixels PXGfor displaying green color, and blue color display pixels PXB fordisplaying blue color. The respective color display pixels are disposedside by side approximately parallel to a direction where the signal lineS extends.

The array substrate AR has a transparent insulating substrate, forexample, a glass and the like. On the transparent insulating substrate,pixel electrodes PE are disposed in the respective display pixels PX.Further, the array substrate AR has plural gate lines G(G(1)-G(M))disposed along a row along which the plural pixel electrodes PE aredisposed, plural signal lines S(S(1)-S(N)) extending along a columnalong which the plural pixel electrodes PE are arranged between theplural pixel electrodes PE, auxiliary capacitance linesCs(Cs(1)-Cs(M+1)) extending approximately parallel to the gate lines G,and plural pixel switches SW disposed in the vicinity of the positionsat which the gate lines G intersect the signal lines S.

Each of the pixel switches SW includes a thin-film transistor (TFT) as,for example, a switching element. The gate of the pixel switch SW iselectrically connected to a gate line G (or formed integrallytherewith). The source of the pixel switch SW is electrically connectedto a signal line S (or formed integrally therewith). The drain of thepixel switch SW is electrically connected to a pixel electrode PE (orformed integrally therewith). That is, the source-drain path of thepixel switch SW is connected between the signal line S and a pixelelectrode PE. When the respective pixel switches SW are driven viacorresponding gate lines G, respectively, the respective pixel switchesSW are conducted between corresponding signal lines S and correspondingpixel electrodes PE.

The liquid crystal display panel LPN includes a first driver (gate/Csdriver) 10 for sequentially driving the plural gate lines G(1)-G(M) toconduct the plural pixel switches SW in, for example, a row unit anddriving also the plural auxiliary capacitance lines Cs(1)-Cs(M+1), and asecond driver (source driver) 20 for outputting a video signal or anon-video signal to the plural signal lines S(1)-S(N), respectivelyduring a period in which the pixel switches SW of the respective rowsare conducted by driving the corresponding gate lines G. The firstdriver 10 and the second driver 20 are drive units for driving the gatelines G, the signal lines S, and the auxiliary capacitance lines Cs.

The first driver 10 and the second driver 20 may be made including anexternally mounted IC or may be formed on the array substrate AR as abuilt-in circuit. In the liquid crystal display apparatus according tothe embodiment, the first driver 10 and the second driver 20 aredisposed in the periphery of the display unit DYP and controlled by thecontrol circuit CTR.

Note that, in FIG. 1, although the first driver 10 is disposed on a leftside of the display unit DYP to a sheet surface, the first driver 10 maybe disposed on a right side depending on a case. Otherwise, two firstdrivers 10 having the same function may be symmetrically disposed onboth the right and left sides. Otherwise, two first drivers 10 may bedisposed on both the right and left sides by being separated to a driverhaving a function for driving the gate line and to a driver having afunction for driving the auxiliary capacitance line Cs, respectively.

The counter substrate CT has a color filter (not illustrated) disposedon a transparent insulating substrate, for example, a glass and the likeand including a color layer of red, green, blue, a common electrode (notillustrated) disposed on the color filter in confrontation with theplural pixel electrodes PE, and the like.

The pixel electrodes PE and the common electrode CE are including atransparent electrode material, for example, ITO and the like andcovered with a pair of orientation films (not illustrated) subjected toa rubbing process in a parallel direction each other, respectively. Therespective pixel electrodes PE and the common electrode CE constitutethe display pixels PX together with pixel regions that are a part theliquid crystal layer LQ controlled by a liquid crystal moleculararrangement corresponding to electric fields from the pixel electrodesPE and the common electrode CE.

The plural color display pixels are classified according to color of acolored layer disposed thereto. The red color display pixel includes ared colored layer. The green display pixel includes a green coloredlayer. The blue color display pixel includes a blue colored layer.

The plural display pixels PX have a liquid crystal capacitance (notillustrated) including the liquid crystal layer LQ held between thepixel electrode PE and the common electrode CE, respectively. The liquidcrystal capacitance is determined by a dielectric constant of a liquidcrystal material, an area of a pixel electrode, and a gap of a liquidcrystal cell.

A voltage applied to a signal line S by the second driver 20(hereinafter, called a source voltage) is applied the pixel electrode PEof the display pixels PX of a selected row by a corresponding pixelswitch SW. A potential difference between a voltage (pixel potential)applied to a pixel electrode PE and a common voltage Vcom applied to acommon electrode CE is held by the liquid crystal capacitance.

Further, an auxiliary capacitor Cst is configured by a part of the pixelelectrode PE (or a semiconductor layer of a switching element) laminatedvia an insulating film and the auxiliary capacitance line Cs(Cs(1)-Cs(M+1)) disposed so as to extend approximately parallel to thegate line G. In a hold period after a signal has been written to thepixel electrode PE, the auxiliary capacitor Cst is coupled with theliquid crystal capacitance.

Note that, although there are a case that the auxiliary capacitor Cst isconnected to an auxiliary capacitance line Cs on an upper side (on oneside in the direction where the signal line S extends) with respect tothe pixel electrode PE and a case that the auxiliary capacitor Cst isconnected to an auxiliary capacitance line Cs on a lower side (the otherside in the direction where the signal line S extends) with respect tothe pixel electrode PE, auxiliary capacitance lines Cs output by theauxiliary capacitor Cst are appropriately distributed so that the loadsof the auxiliary capacitance lines Cs are made roughly uniform inrespective rows.

In an ordinary display operation, the control circuit CTR outputs acontrol signal generated based on a synchronization signal input from anexternal signal source to the first driver 10 and outputs the controlsignal generated based on the synchronization signal input from theexternal signal source and a video signal or a black insertinginversion-transition prevention signal input from an external signalsource to the second driver 20. Further, the control circuit outputs thecommon voltage Vcom applied to the common electrode CE to the countersubstrate CT.

Further, also in a transition drive which is executed prior to a displayat the time of start-up after power has been supplied, the controlcircuit CTR outputs a control signal necessary to execute the transitiondrive to the first driver 10 and outputs a transition voltage signal tothe second driver 20. Further, the control circuit CTR outputs a voltagewaveform necessary to execute the transition drive also to the commonelectrode CE of the counter substrate CT. The transition drive will bedescribed later in detail.

The control signal output from the control circuit CTR to the firstdriver 10 includes a start pulse signal and a clock signal forcontrolling the operation of a shift register of the first driver 10, aCs polarity control signal for controlling the polarity of asuperimposed voltage by the capacitively-coupled coupling, and the like.

Next, a drive method of a 1H1V-CCDI drive that is most fundamental inthe nH1V-CCDI drive will be explained referring to drawings. This is asystem employing a so-called 1H1V inversion in which the arrangement ofa pixel polarity is inverted every other column and the arrangement of apixel polarity is inverted every other row and is a drive method forarranging pixels having a positive polarity and pixels having a negativepolarity are arranged in a checked pattern.

FIG. 2 is a view illustrating a configuration example of an auxiliarycapacitance of a pixel in a liquid crystal display apparatus employing a1H1V-CCDI drive method and an example of a drive waveform.

As an advantage of the 1H1V inversion, since positive and negativepolarities mixedly exist at the time of writing to respective rows andsince coupling from, for example, a signal line S to a common electrodeCE are cancelled by the positive and negative polarities, lateralcrosstalk can be improved. Further, when a dot inversion is employed,there is an advantage that even if a potential of a common electrode isoffset, a line flicker is less viewed.

In the liquid crystal display apparatus for executing the nH1V-CCDIdrive, the auxiliary capacitor Cst of the respective display pixels PXis connected to any of the auxiliary capacitance lines Cs on the upperside and the lower side of a pixel electrode PE to the sheet surface.

When the drive method of the 1H1V-CCDI drive is employed, a destinationto which the auxiliary capacitor Cst of the display pixel PX of eachcolumn is connected is alternately different every other column. Thatis, for example, the auxiliary capacitor Cst of the display pixel PXthat belongs to an odd number column is connected to an upper sideauxiliary capacitance line Cs of the pixel electrode PE, and theauxiliary capacitor Cst of the display pixel PX that belongs to an evennumber column is connected to a lower side auxiliary capacitance line Csof the pixel electrode PE. With the configuration, the polarities ofsignals supplied to the pixel electrodes PE of the destinations to whichthey are connected from the respective auxiliary capacitance lines Csvia the auxiliary capacitances Cst are unified. For example, the signalsall of which have a negative polarity are supplied to the pixelelectrodes PE of the destinations to which they are connected from anauxiliary capacitance line Cs2 via the auxiliary capacitor Cst, and thesignals all of which have a positive polarity are supplied to the pixelelectrodes PE of the destinations to which they are connected from anauxiliary capacitance line Cs3 via the auxiliary capacitor Cst.

This is the same as to the other auxiliary capacitance lines Cs, and, ingeneral, the signals supplied to the pixel electrodes PE from anauxiliary capacitance line Csn (n is an odd number) via the auxiliarycapacitor Cst have the positive polarity, and the signals supplied tothe destination pixel electrodes PE from an auxiliary capacitance lineCsn′ (n is an even number) via the auxiliary capacitor Cst have thenegative polarity. As described above, a desired superimposed voltagecan be applied to the respective display pixels PX without conflict byunifying the polarities of the signals supplied to pixel electrodes PEof the destinations to which they are connected from the respectiveauxiliary capacitance lines Cs via the auxiliary capacitor Cst.

For example, during a period in which the first driver 10 selects a gateline G1, an auxiliary capacitance line Cs1 to which the auxiliarycapacitor Cst of the display pixel PX, to which a video signal of apositive polarity is written, is connected is made to a low voltagestate (L) in the display pixels PX that belong to the row driven by gateline G1. On the one hand, an auxiliary capacitance line Cs2 to which theauxiliary capacitor Cst of the display pixels PX, to which a videosignal of a negative polarity is written, is connected is made to a highvoltage state (H) in the display pixels PX that belong to the row drivenby gate line G1.

After the finish of selection of gate line G1 by the first driver 10, apotential of auxiliary capacitance line Cs1 is transited from the lowvoltage state to the high voltage state, and a potential of auxiliarycapacitance line Cs2 is transited from the high voltage state to the lowvoltage state. As a result, a positive superimposed voltage is appliedto the display pixels PX, to which the video signal of the positivepolarity is written, via the auxiliary capacitor Cst in the displaypixels PX that belong to the row driven by gate line G1, and a negativesuperimposed voltage is applied to the display pixels PX, to which thevideo signal of the negative polarity is written, via the auxiliarycapacitor Cst in the display pixels PX that belong to the row driven bygate line G1.

Next, an auxiliary capacitance line Cs3 to which the auxiliary capacitorCst of the display pixel PX, to which the video signal of the positivepolarity is written, is connected is made to a low voltage state in thedisplay pixels PX that belong to the row driven by gate line G2. On theone hand, an auxiliary capacitance line Cs2 to which the auxiliarycapacitor Cst of the display pixels PX, to which the video signal of thenegative polarity is written, is connected is made to a high voltagestate in the display pixels PX that belong to the row driven by gateline G2 during a period in which gate line G2 is selected.

After the finish of selection of gate line G2 by the first driver 10, apotential of auxiliary capacitance line Cs3 is transited from the lowvoltage state to the high voltage state, and the potential of auxiliarycapacitance line Cs2 is transited from the high voltage state to the lowvoltage state. As a result, the positive superimposed voltage is appliedto the display pixels PX, to which the video signal of the positivepolarity is written, via the auxiliary capacitor Cst in the displaypixels PX that belong to the row driven by gate line G2, and thenegative superimposed voltage is applied to the display pixels PX, towhich the video signal of the negative polarity is written, via theauxiliary capacitor Cst in the display pixels PX that belong to the rowdriven by gate line G2.

Hereinafter, this is the same as to gate lines G3, G4, . . . , and as toall the display pixels PX in the display unit DYP, the positivesuperimposed voltage is applied to the display pixels PX, to which thevideo signal of the positive polarity is written, via the auxiliarycapacitor Cst, and the negative superimposed voltage is applied to thedisplay pixels PX, to which the video signal of the negative polarity iswritten, via the auxiliary capacitor Cst.

Note that, in the above explanation, although auxiliary capacitancelines Cs2 applies the superimposed voltage to both the display pixels PXof the row selected by gate line G1 and the display pixels PX of the rowselected by gate line G2, the potential of auxiliary capacitance linesCs2 after the finish of selection of any of gate lines G1 and G2 istransited from the high voltage state to low voltage state and noconflict occurs therebetween.

This is the same as to the other auxiliary capacitance lines Cs, forexample, auxiliary capacitance lines Cs3, Cs4, . . . , and although thesuperimposed voltage is applied to successive two rows, since thetransition of the potential of the auxiliary capacitance lines after thegate line G has been selected is common in any ones of the two rows, noconflict occurs. As explained above, this is because the polarities ofthe signals supplied to the pixel electrodes PE of the destinations towhich they are connected from the respective auxiliary capacitance linesCs via the auxiliary capacitor Cst are unified.

As described above, a pixel holding voltage amplitude, which is largerthan a range (video signal amplitude) of a signal voltage applied fromthe signal line S to the pixel electrodes PE, can be obtained byapplying the superimposed voltage in conformity with the polarities ofthe display pixels PX. With the operation, the second driver 20 having asmall voltage amplitude can be used, thereby a driver cost and powerconsumption can be reduced.

Next, the 2H1V-CCDI drive will be explained as a different exampleaccording to the embodiment using FIG. 11.

FIG. 3 is a view illustrating a configuration example of an auxiliarycapacitance of a pixel in a liquid crystal display apparatus employingthe 2H1V-CCDI drive method and an example of a drive waveform.

The 2H1V-CCDI drive is the same as the 1H1V-CCDI in that the arrangementof pixel polarity is inverted every other column as to a columndirection, in the 2H1V-CCDI drive, the arrangement of pixel polarity isinverted every second row.

The 2H1V-CCDI drive is advantageous in that lower power can be realizedas compared with the 1H1V-CCDI drive. That is, although the polarity thevideo signal is inverted every other horizontal period (1H) in the 1H1Vinversion, since the polarity of the video signal is inverted everysecond horizontal period (2H) in the 2H1V inversion, a signal linecharge/discharge frequency becomes half that of the 1H1V inversion andthus power consumption is reduced.

In the 2H1V-CCDI drive, to apply a superimposed voltage that is inconformity with the polarity of the respective display pixels PX to therespective display pixels PX, it is sufficient to determine thearrangement of the auxiliary capacitor Cst as described below. First,positive or negative polarity is allocated to the respective auxiliarycapacitance lines Cs every other row. For example, positive is allocatedto auxiliary capacitance lines Cs1, Cs3, Cs5, . . . , and negative isallocated to auxiliary capacitance lines Cs2, Cs4, Cs6, . . . .

When the polarity is allocated to the auxiliary capacitance lines Cs asdescribed above, ones of the upper and lower auxiliary capacitance linesCs become positive and the others thereof become negative as to all thedisplay pixels PX. Accordingly, it is sufficient to dispose theauxiliary capacitor Cst between the auxiliary capacitance lines Cs thatare in conformity with the polarity of a video signal written to therespective display pixels PX. As a result, the polarity of thesuperimposed voltage to the pixel electrodes PE connected from, forexample, the positive auxiliary capacitance lines Cs via the auxiliarycapacitor Cst is entirely made to positive, and the polarity of thesuperimposed voltage to the pixel electrodes PE connected from thenegative auxiliary capacitance lines Cs via the auxiliary capacitor Cstis entirely unified to negative. With the operation, the superimposedvoltage can be applied to the respective display pixels PX withoutconflict of polarity.

As illustrated in FIG. 3, when the 2H1V-CCDI drive is employed, the2H1V-CCDI drive is different from the 1H1V-CCDI drive in that, in theauxiliary capacitors Cst of the display pixels PX that belong to therespective columns, the auxiliary capacitors Cst which are disposed onan upper side and the auxiliary capacitors Cst which are disposed on alower side mixedly exist.

Note that since a drive waveform of the 2H1V-CCDI drive is entirely thesame as that of the 1H1V-CCDI drive and a specific drive procedure ofthe 2H1V-CCDI drive is entirely the same as that of the 1H1V-CCDI drive,the explanation thereof is not repeated here.

In the 2H1V-CCDI drive described above, when a polarity inversion cycleof the video signal is more increased, the 2H1V-CCDI drive can beexpanded to the nH1V-CCDI drive (n is an integer of 3 or more). When thepolarity of the video signal is inverted every nH, there can be obtaineda merit that power consumed to charge and discharge a signal line can bereduced in proportion to 1/n. However, when n becomes large, since alateral stripe and a line flicker that appear at an n-row pitch maybecome outstanding, it is preferable to select an optimum value of n inview of a specification requested to image quality and powerconsumption.

FIG. 4 is a view illustrating a configuration example of an auxiliarycapacitor of a pixel in a liquid crystal display apparatus employing a4H1V-CCDI drive method and an example of a drive waveform.

In the liquid crystal display apparatus employing the 4H1V-CCDI drivemethod, a method of determining the arrangement of the auxiliarycapacitor Cst is the same as that of the 2H1V-CCDI drive. That is,positive or negative polarity is allocated to the respective auxiliarycapacitance lines Cs every other row. For example, the positive polarityis allocated to auxiliary capacitance lines Cs1, Cs3 and Cs5, and thenegative polarity is allocated to auxiliary capacitance lines Cs2, Cs4and Cs6.

When the polarity is allocated to the auxiliary capacitance lines Cs asdescribed above, since ones of the upper and lower auxiliary capacitancelines Cs become positive and the others thereof become negative as toall the display pixels PX, it is sufficient to dispose the auxiliarycapacitor Cst between the auxiliary capacitance lines Cs that are inconformity with the polarity of the video signal written to therespective display pixels PX.

Since, for example, the polarity of the superimposed voltage to thepixel electrodes PE connected from the positive auxiliary capacitancelines Cs via the auxiliary capacitor Cst is entirely unified to positiveand the polarity of the superimposed voltage to the pixel electrodes PEconnected from the negative auxiliary capacitance lines Cs via theauxiliary capacitor Cst is entirely unified to negative, thesuperimposed voltage can be applied to the respective display pixels PXwithout conflict of polarity.

FIG. 4 illustrates a configuration example of the auxiliary capacitorCst of the display pixels PX with the auxiliary capacitor Cst beingdisposed as described above. Also in the case, it is the same as the2H1V-CCDI drive that, in the auxiliary capacitors Cst of the displaypixels PX that belong to the respective columns, the auxiliarycapacitors Cst which are disposed on the upper side and the auxiliarycapacitors Cst which are disposed on the lower side mixedly exist.

Since a drive waveform is entirely the same waveform as that of the1H1V-CCDI drive and the 2H1V-CCDI drive and a specific drive procedureis also entirely the same, the explanation thereof is not repeated here.

Note that, when n is increased and set to a limit n and n is caused toagree with the number of all the lines (number of all the gate lines),the polarity of all the display pixels PX in a row becomes the same,which results in a CC column inversion drive system. Also in the CCcolumn inversion drive system, it is possible to apply the superimposedvoltage, which is in conformity with the polarity of the respectivedisplay pixels PX, to the respective display pixels PX by determiningthe arrangement of the auxiliary capacitor Cst by an entirely similarrule. Although the CC column inversion drive system is advantageous inthat it consumes a small amount of power and neither a lateral stripenor a line flicker is generated, longitudinal crosstalk may be generatedeasily. It is possible to employ the CC column inversion drive systemtaking the points into consideration. From what has been describedabove, it is possible to regard that the CC column inversion drive isalso included in the CCDI drive in a wide sense.

The liquid crystal display apparatuses of the nH1V-CCDI drive (n is aninteger of 1 or more) according to the embodiment have been explainedabove, a point common to the apparatuses is that the auxiliarycapacitors Cst of the display pixels PX disposed on the upper side andthe auxiliary capacitors Cst of the display pixels PX disposed on theupper side mixedly exist. A pixel layout in the liquid crystal displayapparatuses will be explained below. Note that the case of the 2H1V-CCDIdrive will be mainly explained below as an example.

Next, the pixel layout of the liquid crystal display apparatuses will beexplained using FIG. 5 to FIG. 7.

FIG. 5 is a view illustrating an example of a pixel layout of a liquidcrystal display apparatus of a first embodiment, and a portioncorresponding to two pixels (pixel A, pixel B) surrounded by a brokenline in a pixel arrangement of FIG. 1 is drawn.

A pixel electrode PE is disposed in a region surrounded by a signal lineS and an auxiliary capacitance line Cs and is disposed by beingoverlapped with parts of the signal line S and the auxiliary capacitanceline Cs.

The gate line G is disposed to approximately the central portion of thepixel electrode PE in a direction where the signal line S extends andextends in a direction where the gate line G is approximately orthogonalto the signal line S.

A pixel switch SW extends up to a lower layer of the auxiliarycapacitance line Cs so as to intersect the gate line G in a lower layerof the signal line S and has an approximately T-shaped semiconductorlayer PS that extends in a direction where the auxiliary capacitanceline Cs extends in the lower layer of the auxiliary capacitance line Cs.A portion where the semiconductor layer PS overlaps the auxiliarycapacitance line Cs extends up to a left pixel region exceeding a leftsignal line S. This is to prevent both the semiconductor layers PS frominterfering with each other in a portion where it is necessary to formthe auxiliary capacitor Cst to a common auxiliary capacitance line Cs asin, for example, pixel B and a pixel thereunder and to prevent anopening rate from being reduced by effectively making use of a regionthat overlaps the auxiliary capacitance line Cs.

The semiconductor layer PS is electrically connected to the signal lineS in a contact hole HL2 disposed to one side of a portion thatintersects the gate lines G. The semiconductor layer PS extends to theauxiliary capacitance line Cs side on the other side of a portion thatintersects the gate line and is electrically connected to the pixelelectrode PE in a contact hole HL1 disposed to a portion where thesemiconductor layer PS overlaps the pixel electrodes PE via the contactelectrode EC. Note that, in the embodiment, the pixel switch SW may bean amorphous silicon layer having a polysilicon layer as thesemiconductor layer PS.

The semiconductor layer PS extends from the lower layer of the signalline S to the auxiliary capacitance line Cs side to which the auxiliarycapacitor Cst of a corresponding display pixel PX is connected. Thesemiconductor layer PS of the pixel switch SW that switches a connectionof the pixel electrode PE of pixel A and the signal line S extends fromthe lower layer of the signal line S to the auxiliary capacitance linesCs on an upper side and extends in a direction where the auxiliarycapacitance line Cs extends in the lower layer of the auxiliarycapacitance line Cs on the upper side. The semiconductor layer PS of thepixel switch SW that switches a connection of the pixel electrode PE ofpixel B and the signal line S extends from the lower layer of the signalline S to the auxiliary capacitance lines Cs on the lower side andextends in a direction where the auxiliary capacitance line Cs extendsin the lower layer of the auxiliary capacitance line Cs on the lowerside.

The contact electrode EC is formed in an approximately rectangular shapeand a part thereof is disposed inside of pixels A and B with respect toan end side extending approximately parallel to the gate line G of theauxiliary capacitance line Cs.

The auxiliary capacitance line Cs extends approximately parallel to adirection in which the gate line G extends. The auxiliary capacitanceline Cs includes a concave portion CsB disposed at the position wherecontact hole HL1 of an end which extends approximately parallel to thegate line G is disposed and a convex portion CsA that projects inside ofpixels A and B from the end which extends approximately parallel to thegate line G. A set of the convex portion CsA and the concave portion CsBis disposed to the auxiliary capacitance line Cs positioned to both theends in the direction where the signal lines S of respective pixels Aand B extend.

Accordingly, openings A1, A2, B1 and B2 of pixels A and B become regionssurrounded by the end of the gate line G, the signal line S, and theauxiliary capacitance line Cs including the convex portion CsA and thecontact electrode EC.

FIG. 6 is a view illustrating an example of a sectional structure of aliquid crystal display panel taken along line VI-VI in FIG. 5. FIG. 6illustrates an example of a sectional structure of a boundary portion oftwo display pixels PX disposed side by side in the direction where thesignal line S extends.

As illustrated in FIG. 5 and FIG. 6, the auxiliary capacitor Cst isformed across an insulating layer (insulating film) between an electrode(semiconductor layer electrode) of the semiconductor layer (for example,a polysilicon [p-Si] layer) PS and the auxiliary capacitance lines Cs. Asemiconductor layer electrode of the auxiliary capacitor Cst iselectrically connected to the pixel electrode PE via the contactelectrode EC by contact hole HL1 and has the same potential as that ofthe pixel electrode PE. Note that contact hole HL1 includes a contacthole HL11 and a contact hole HL12.

The semiconductor layer PS (semiconductor electrode) is disposed on atransparent insulating substrate of an array substrate AR. In a crosssection of the array substrate AR, two semiconductor layers PS aredisposed side by side in a direction approximately orthogonal to thedirection where the auxiliary capacitance line Cs extends.

The auxiliary capacitance line Cs is disposed on an upper layer of thesemiconductor layer PS via a gate insulating film L1. The auxiliarycapacitance line Cs is disposed so as to overlap a part of thesemiconductor layer PS on one hand and the semiconductor layer PS on theother hand in its entirety. That is, the auxiliary capacitance line Cshas the concave portion CsB formed at the position where contact holeHL1 is disposed, and a part of an upper layer of the semiconductor layerPS on the other hand is removed. The contact electrode EC is disposed onan upper layer of the auxiliary capacitance line Cs via an interlayerinsulating film L2.

The contact electrode EC is electrically connected to the semiconductorlayer PS on the one hand by the gate insulating film L1 on thesemiconductor layer PS on the one hand and contact hole HL11 passingthrough the interlayer insulating film L2 at a position where aconductive layer is removed by the concave portion CsB of the auxiliarycapacitance line Cs. The pixel electrode PE is disposed on an upperlayer of the contact electrode EC via an organic insulating film L3.

The pixel electrode PE is disposed side by side in a directionapproximately orthogonal to the direction where the auxiliarycapacitance line Cs extends. Contact hole HL12 that passes through theorganic insulating film L3 is disposed in a portion where the pixelelectrode PE on the one hand overlaps the contact electrode EC. Thepixel electrode PE on the one hand is electrically connected to thecontact electrode EC in contact hole HL12.

A not illustrated orientation film is disposed on the pixel electrodePE. A surface of the orientation film is subjected to an orientationprocess such as a rubbing process, an optical orientation process, andthe like in a predetermined direction.

A counter substrate CT has a color filter (not illustrated) and a commonelectrode CE disposed on the transparent insulating substrate such as aglass, and the like. The common electrode CE is disposed to confrontplural pixel electrodes PE. An orientation film (not illustrated) isdisposed on the common electrode CE, and a surface thereof is subjectedto an orientation process such as a rubbing process, an opticalorientation process, and the like in a predetermined direction.

FIG. 7 is a view illustrating a sectional structure of the liquidcrystal display panel taken along line VII-VII in FIG. 5. FIG. 7illustrates an example a sectional structure in line VII-VIIapproximately parallel to the signal line S at the position where thegate lines G intersects the signal line S.

The semiconductor layer PS is disposed on the transparent insulatingsubstrate of the array substrate AR. The gate line G is disposed on theupper layer of the semiconductor layer PS via the gate insulating filmL1. The signal line S is disposed on an upper layer of the gate line Gvia the interlayer insulating film L2. The organic insulating film L3 isdisposed on the signal line S.

Contact hole HL2 is disposed to the gate insulating film L1 and theinterlayer insulating film L2 on the end to which the semiconductorlayer PS extends. The signal line S is electrically connected to thesemiconductor layer PS in contact hole HL2.

The semiconductor layer PS intersects the gate line across theinsulating film in a portion corresponding to a longitudinal rod of theT-type semiconductor layer PS, and the pixel switch SW is formed in theportion. A source side of pixel switch SW is electrically connected tothe signal line S in contact hole HL2, and a drain side thereof isformed integrally with the semiconductor layer electrode of theauxiliary capacitor Cst. Note that the gate line G functions as a gateelectrode of the pixel switch SW.

A configuration of the counter substrate CT is the same as thatillustrated in FIG. 6, the explanation thereof is not repeated here.

In the embodiment, openings A1 and B1 on the upper side of the gate lineG are disposed approximately in line symmetry with respect to openingsA2 and B2 on the lower side of the gate line G to the gate line G inrespective pixels A and B by disposing the convex portion CsA to theauxiliary capacitance line Cs as described above.

In other words, in openings A1 and A2 and openings B1 and B2 which aresurrounded by the gate line G, the signal line S, the auxiliarycapacitance line Cs including the convex portion CsA, and an end of thecontact electrode EC and disposed side by side in the direction wherethe gate line G extends, the positions of centers of gravity of openingsA1 and A2 are made the same as those of openings B1 and B2 in thedirection where the signal line S extends by disposing the convexportion CsA to the auxiliary capacitance line Cs as described above.

That is, display pixel A includes opening A1 (first opening) on one sideof the gate line G in the direction where the signal line S extends andopening A2 (second opening) on the other side of the gate line G.

Opening A1 (first opening) is formed in a concave shape (approximatelyU-shape) surrounded by the gate line G, the signal line S, the auxiliarycapacitance line Cs, and the end of the contact electrode EC. Opening A2(second opening) is formed in a concave shape (approximately ∩-shape)surrounded by the gate line G, the signal line S, and the end of theauxiliary capacitance line Cs including the convex portion CsA. OpeningA1 is disposed approximately in line symmetry with respect to opening A2in the direction where the gate line G extends.

Likewise, display pixel B includes opening B2 (first opening) on oneside of the gate line G in the direction where the signal line S extendsand opening B1 (second opening) on the other side of the gate line G.

Opening B2 (first opening) is formed in a concave shape (approximatelyU-shape) surrounded by the gate line G, the signal line S, the auxiliarycapacitance line Cs, and the end of the contact electrode EC. Opening B1(second opening) is formed in a concave shape (approximately ∩-shape)surrounded by the gate line G, the signal line S, and the end of theauxiliary capacitance line Cs including the convex portion CsA. OpeningB2 is disposed approximately in line symmetry with respect opening B1 inthe direction where the gate line G extends.

That is, in respective pixels A and B, the contact electrode EC isdisposed to a portion where the pixel electrode PE is electricallyconnected to the semiconductor layer PS, and the contact electrode EC isdisposed extending inside of pixels A and B. Accordingly, opening A1 ofpixel A and opening B2 of pixel B have portions that are shaded by apart of the contact electrode EC and concaved inside.

In the embodiment, in pixel A, the convex portion CsA of the auxiliarycapacitance line Cs on the lower side is disposed extending inside ofpixel A so that opening A2 to which the contact electrode EC is notdisposed is in line symmetry with respect to opening A1. In pixel B, theconvex portion CsA of the auxiliary capacitance line Cs on the upperside is disposed extending inside of pixel B so that opening B1 to whichthe contact electrode EC is not disposed is in line symmetry withopening B2.

When a case that the convex portion CsA is not disposed to the auxiliarycapacitance line Cs is examined, since light is shaded in the portionwhere the contact electrode EC is disposed, the openings are offsetbetween the upper side and the lower side of pixels A and B.

In pixel A, the pixel electrode PE is electrically connected to thesemiconductor layer PS via the contact electrode EC in the concaveportion CsB of the auxiliary capacitance line Cs on the upper side.Accordingly, in pixel A, since a shaded portion is formed on an upperend by the contact electrode EC, a dark portion of the upper end becomeslarge.

In pixel B, the pixel electrodes PE is electrically connected to thesemiconductor layer PS via the contact electrode EC in the concaveportion CsB of the auxiliary capacitance line Cs on the lower side.Accordingly, in pixel B, since a shaded portion is formed on a lower endby the contact electrode EC, a dark portion of the lower end becomeslarge.

For example, in a pixel disposed on the lower side of pixel B, the pixelelectrode PE is electrically connected to the semiconductor layer PS viathe contact electrode EC in the concave portion CsB of the auxiliarycapacitance line Cs disposed on the upper side. Accordingly, in thepixel, since a shaded portion is formed on the upper end by the contactelectrode EC, a dark portion of the upper end becomes large.

Accordingly, in the vicinity of the auxiliary capacitance line Cs on thelower side of pixel B, a dark portion is generated to a lower end ofpixel B on the lower side and a dark portion is generated to an upperend of the pixel on the lower side.

In contrast, in a pixel disposed on the lower side of pixel A, the pixelelectrode PE is electrically connected to the semiconductor layer PS viathe contact electrode EC in the concave portion CsB of the auxiliarycapacitance line Cs disposed on the lower side. Accordingly, in thepixel, since a shaded portion is formed on the lower end by the contactelectrode EC, a dark portion of the lower end becomes large.

Accordingly, in the vicinity of the auxiliary capacitance line Cs on thelower side of pixel A, no shaded portion is generated by the contactelectrode EC, an opening portion becomes large in comparison with thevicinity of the auxiliary capacitance line Cs on the lower side of pixelB.

In the case, when a halftone solid display (monotone display), a stripedisplay (1V longitudinal stripe display) of every other row, a dotdisplay of checked pattern (dot-check display) are executed, a brightline and a dark line, which are approximately parallel to the gate lineG, are periodically generated, thereby display quality may be lowered.

In contrast, when openings A1 and B1 on the upper side are formedapproximately in line symmetry with respect to openings A2 and B2 on thelower side to the gate line G, no offset is caused between thebrightness of the upper end of the pixel and the brightness of the lowerend of the pixel, thereby display quality is not lowered.

FIG. 8 is a view illustrating an example of a display pattern when amonotone display is executed in the liquid crystal display apparatusemploying the 2H1V-CCDI drive system. It is illustrated here that awhite pixel shows a bright display (for example, white) and a pixelcolored with black shows a dark display (for example, black).

When a minimum unit is extracted as a combination of the disposition ofthe auxiliary capacitor Cst (whether disposed on an upper side or on alower side) and a display gradation (whether bright or dark), a portionsurrounded by a frame FR1 is obtained as the minimum unit. A displaypattern of an overall screen is configured by two-dimensionallyrepeating the minimum unit. In the monotone display, the minimum unithas a two-row cycle.

Here, attention is paid to the auxiliary capacitance line Cscorresponding to a boundary of display pixels PX which are adjacent toeach other above and below and a pattern (portion surrounded by a frameFR2) in the vicinity thereof. When no convex portion CsA is disposed tothe auxiliary capacitance line Cs, although a dark portion by thepattern of the contact electrode EC is differently disposed every otherrow, the number of disposed contact electrodes EC is the same inrespective rows. Accordingly, the brightness of the portion surroundedby frame FR2 is approximately the same in the respective rows and nobight/dark pattern is generated at a cycle larger than a pixel pitch.

When the convex portion CsA is disposed to the auxiliary capacitanceline Cs, a dark portion by the pattern of the contact electrode EC andthe convex portion CsA are disposed likewise in the respective rows, andthe number of dark portions is also the same in the respective rows.Accordingly, also in the case, the brightness of the portion surroundedby frame FR2 is approximately the same in the respective rows, and nobight/dark pattern is generated at the cycle larger than the pixelpitch.

FIG. 9 is a view illustrating an example of a display pattern when a 1Vstripe is displayed in the liquid crystal display apparatus employingthe 2H1V-CCDI drive system. It is illustrated here that a white pixelshows a bright display (for example, white) and a pixel colored withblack shows a dark display (for example, black).

Likewise the case of the monotone display, when a minimum unit isextracted as a combination of the disposition of the auxiliary capacitorCst (whether disposed on an upper side or on a lower side) and a displaygradation (whether bright or dark), a portion surrounded by a frame FR1is obtained as the minimum unit. A display pattern of an overall screenis configured by two-dimensionally repeating the minimum unit. In the 1Vlongitudinal stripe display, the minimum unit has a four-row cycle.

Here, attention is paid to the auxiliary capacitance line Cscorresponding to a boundary of display pixels PX which are adjacent toeach other above and below and a pattern (portion surrounded by a frameFR2) in the vicinity thereof. When no convex portion CsA is disposed tothe auxiliary capacitance line Cs, a portion where a dark portion by thepattern of the contact electrode EC does not exist at all and a portionwhere dark portions by the pattern of the contact electrode EC existsabove and below respective columns appear every second column. Since theformer portion is recognized relatively bright and the latter portion isrecognized relatively dark, when the former and latter portions arevisually recognized in broad perspective, they are visually recognizedas if bright and dark patterns exist at a four-row cycle.

In contrast, when the convex portion CsA is disposed to the auxiliarycapacitance line Cs, a dark portion by the pattern of the contactelectrode EC and the convex portion CsA are disposed likewise in therespective rows, and the number of dark portions is also the same in therespective rows. Accordingly, also in the case, the brightness of theportion surrounded by frame FR2 is approximately the same in therespective rows and no bight/dark pattern is generated at a cycle largerthan a pixel pitch.

FIG. 10 is a view illustrating an example of a display pattern when adot-check display is executed in the liquid crystal display apparatusemploying the 2H1V-CCDI drive system. It is illustrated here that awhite pixel shows a bright display (for example, white) and a pixelcolored with black shows a dark display (for example, black).

Likewise the case of the monotone display, when a minimum unit isextracted as a combination of the disposition of the auxiliary capacitorCst (whether disposed on an upper side or on a lower side) and a displaygradation (whether bright or dark), a portion surrounded by a frame FR1is obtained as the minimum unit. A display pattern of an overall screenis configured by two-dimensionally repeating the minimum unit. In thedot-check display, the minimum unit has a four-row cycle.

Here, attention is paid to the auxiliary capacitance line Cscorresponding to a boundary of display pixels PX which are adjacent toeach other above and below and a pattern (portion surrounded by a frameFR2) in the vicinity thereof. When no convex portion CsA is disposed tothe auxiliary capacitance line Cs, a portion where a dark portion by thepattern of the contact electrode EC does not exist at all and a portionwhere a dark portion by the pattern of the contact electrode ECalternately exist above and below appear every second row. Since theformer portion is recognized relatively bright and the latter portion isrecognized relatively dark, when the former and latter portions arevisually recognized in broad perspective, they are visually recognizedas if bright and dark patterns exist at a four-row cycle.

In contrast, when the convex portion CsA is disposed to the auxiliarycapacitance line Cs, a dark portion by the pattern of the contactelectrode EC and the convex portion CsA are disposed likewise in therespective rows, and the number of dark portions is also the same in therespective rows. Accordingly, also in the case, the brightness of theportion surrounded by frame FR2 is approximately the same in therespective rows and no bight/dark pattern is generated at a cycle largerthan a pixel pitch.

As described, when the convex portion CsA is disposed to the auxiliarycapacitance line Cs, since the display pixel PX forms the convex portionCsA to the auxiliary capacitance line Cs and places the pixel openingsin upper and lower symmetry, the shape of openings is made approximatelysimilar regardless that the auxiliary capacitor Cst of the displaypixels PX is disposed above or below. Accordingly, the number of convexportions CsA of the auxiliary capacitance line Cs surrounded by frameFR2 is the same in the respective rows, a defective display, in which abright/dark cycle pattern (lateral stripe) appears at a cycle largerthan a pixel pitch, is eliminated, and display quality can be suppressedfrom being lowered regardless of a display pattern.

That is, according to the embodiment, a liquid crystal display apparatusfor suppressing display quality from being lowered can be provided.

FIG. 11 is a view illustrating an example of a pixel layout of a liquidcrystal display apparatus of a second embodiment, and a portioncorresponding to the two pixels (pixel A, pixel B) surrounded by thebroken line in the pixel arrangement of FIG. 1 is drawn in FIG. 11. Notethat, in the following explanation, the same configurations as those ofthe first embodiment described above are denoted by the same referencenumbers and are not explained repeatedly.

In the embodiment, although no convex portion CsA is disposed to anauxiliary capacitance line Cs, in a display pixel PX in which anauxiliary capacitor Cst is connected to an upper auxiliary capacitanceline Cs (auxiliary capacitor Cst is connected to an upper side), a gateline G is curved downward and, in a display pixel PX in which anauxiliary capacitor Cst is connected to a lower auxiliary capacitanceline Cs (auxiliary capacitor Cst is connected to a lower side), a gateline G is curved upward.

That is, in openings A1 and A2 and openings B1 and B2 which aresurrounded by the gate line G, a signal line S, the auxiliarycapacitance line Cs including the convex portion CsA, and an end of acontact electrode EC and disposed in the direction where the gate line Gextends, the positions of center of gravity of openings A1 and A2 aremade the same as those of openings B1 and B2 in the direction where thesignal line S extends by curving the gate line G.

Here, the position of center of gravity of the opening of each displaypixel PX in an up/down direction (direction approximately parallel tothe signal line S) is given by yG of (Expression 1) described below,wherein the direction where the gate line G and the auxiliarycapacitance line Cs extend is shown by an x-direction, the directionwhere the signal line S extends is shown by a y-direction, and theposition of center of gravity is shown by a two-dimensional coordinateof (x, y).

$\begin{matrix}{y_{G} = \frac{\int_{A}{y{x}{y}}}{\int_{A}{{x}{y}}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

It is assumed here that a domain of integration A is a pixel openingregion (a sum of the area of opening A1 and the area of opening A2 or asum of the area of opening B1 and the area of opening B2) in (x, y)plane.

Otherwise, to more precisely determine the domain of integration A, itmay be determined by (Expression 2) described below by performingweighting by a transmittance distribution T(x, y) of a pixel opening.

$\begin{matrix}{y_{G} = \frac{\int_{A}{{{yT}\left( {x,y} \right)}{x}{y}}}{\int_{A}{{T\left( {x,y} \right)}{x}{y}}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

In other words, it is because the position of center of gravity of anopening is different between a display pixel PX having an auxiliarycapacitor Cst disposed to an upper side and a display pixel PX having anauxiliary capacitor Cst disposed to a lower side in an up/don directionthat a bright/dark pattern is generated at a cycle larger than a pixelpitch in a particular display pattern as described above.

That is, when a display pixel PX having an opening whose center ofgravity is offset downward exists on an upper side and a display pixelPX having an opening whose center of gravity is offset upward exists ona lower side using a certain auxiliary capacitance line Cs as areference, the vicinity of the auxiliary capacitance line Cs is feltrelatively bright. Conversely, when a display pixel PX having an openingwhose center of gravity is offset upward exists on an upper side and adisplay pixel PX having an opening whose center of gravity is offsetdownward exists on a lower side using a certain auxiliary capacitanceline Cs as a reference, the vicinity of the auxiliary capacitance lineCs is felt relatively dark.

When a pixel A illustrated in FIG. 11 has a contact electrode ECextending from an upper auxiliary capacitance line Cs downward and thegate line G extending in the x-direction and is formed in anapproximately linear shape, an opening A1 of pixel A becomes small.Accordingly, the gate line G is curved downward to prevent the center ofgravity of the opening from being offset downward by the influence ofthe contact electrode EC.

When a pixel B illustrated in FIG. 11 has a contact electrode ECextending from a lower auxiliary capacitance line Cs upward and the gateline G extending in the x-direction and is formed in an approximatelylinear shape, an opening B2 of pixel B becomes small. Accordingly, thegate line G is curved upward to prevent the center of gravity of theopening from being offset upward by the influence the contact electrodeEC.

Since the center of gravity of the opening of pixel A is moved upwardand the center of gravity of the opening of pixel B is moved downward bycurving the gate line G as described above, the offset of the positionsof center of gravity of pixel A and pixel B in the up/down direction canbe cancelled. As a result, when displays such as the 1V longitudinalstripe display or the dot-check display and the like are executed, adefective display, in which a lateral stripe is visually recognized at4-row pitch, is eliminated and display quality can be suppressed frombeing lowered.

Although the liquid crystal display apparatus employing the 2H1V-CCDIdrive has been explained above, other CCDI drives will be also examined.

When A, a monotone display; B, a 1V longitudinal stripe display; and C,a dot-check display are executed, respectively by a liquid crystaldisplay apparatus which has two types of pixels having a differentposition of center of gravity because a display pixel PX having anauxiliary capacitor Cst disposed to an upper side and a display pixel PXhaving an auxiliary capacitor Cst disposed to a lower side are mixedlyexist therein, at what cycle a lateral stripe is generated will beexamined below using FIG. 12 to FIG. 15.

In FIG. 13 to FIG. 15, ↑ illustrates a display pixel PX having anopening whose center of gravity is offset upward, ↓ illustrates adisplay pixel PX having an opening whose center of gravity is offsetdownward, and a hatched portion illustrates a display pixel PX of darkdisplay (for example, black). Further, in the respective displaypatterns, when attention is paid to a boundary line that corresponds toan upper/lower side of display pixels PX, that is, attention is paid tothe vicinity of the auxiliary capacitance line Cs and the positions ofcenter of gravity of the openings of the display pixels PX which executea bright display in the display pixels PX of the upper and lower rowsare located near to the boundary line (that is, when a rate of thedisplay pixels PX the arrows of which face the boundary lines is largerthan half), the boundary line is shown as bright. Further, when thepositions of center of gravity of the openings of the display pixels PXwhich execute the bright display in the display pixels PX of the upperand lower rows are not located near to the boundary line (that is, whenthe rate of the display pixels PX the arrows of which face the boundarylines is smaller than half), the boundary line is shown as dark.

FIG. 12 is a view illustrating an offset of center of gravity of anopening of a pixel as to the respective display patterns in the liquidcrystal display apparatus employing the 1H1V-CCDI drive.

As illustrated in FIG. 12, when the 1H1V-CCDI drive is employed,although no lateral stripe is generated in the monotone display and the1V longitudinal stripe display, a lateral stripe is generated in thedot-check display every other row.

FIG. 13 is a view illustrating the offset of center of gravity of anopening of a pixel as to the respective display patterns in the liquidcrystal display apparatus employing a 2H1V-CCDI drive.

As illustrated in FIG. 13, when the 2H1V-CCDI drive is employed,although no lateral stripe is generated in the monotone display, alateral stripe is generated in the 1V longitudinal stripe display andthe dot-check display every second row.

FIG. 14 is a view illustrating an offset of center of gravity of anopening of a pixel as to the respective display patterns in the liquidcrystal display apparatus employing the 4H1V-CCDI drive.

As illustrated in FIG. 14, when the 4H1V-CCDI drive is employed,although no lateral stripe is generated in the monotone display, plurallateral stripes are generated in the 1V longitudinal stripe display atan eight-row cycle, and a lateral stripe is generated in the dot-checkdisplay every fourth row.

FIG. 15 is a view illustrating an offset of center of gravity of anopening of a pixel as to the respective display patterns in a liquidcrystal display apparatus employing the CC column inversion drive.

As illustrated in FIG. 15, when the CC column inversion drive isemployed, although no lateral stripe is generated in the monotonedisplay and the dot-check display, a lateral stripe is generated in the1V longitudinal stripe display every other row.

In contrast, in the liquid crystal display apparatuses of the firstembodiment and the second embodiment, since the center of gravity of theopening of the display pixel PX is not offset, the lateral stripe can beprevented from being generated in any of the drives described above.

That is, according to the embodiments described above, a liquid crystaldisplay apparatus for suppressing display quality from being lowered canbe provided.

Note that a larger bright/dark pitch makes it easier to visuallyrecognize the lateral stripe. From the viewpoint, when, in particular, nin the nH1V-CCDI drive is larger than 2, (however, the CC columninversion drive is excluded), since a lateral stripe having a cycle of4-row or more pitch can be avoided from being generated, it can be saidthat high image quality improving effect can be obtained.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

The liquid crystal display apparatuses of the embodiments describedabove do not particularly restrict a liquid crystal mode and can beapplied to various modes such as a TN (Twisted Nematic) mode, an OCB(Optically Compensated Bend) mode, a VA (vertically aligned) mode, anIPS (in-plane switching) mode, and an FFS (fringe field switching) mode.

FIG. 16 is a view illustrating other configuration example of anauxiliary capacitor of a pixel in the liquid crystal display apparatusemploying the 2H1V-CCDI drive method and other example of the drivewaveform.

In the IPS mode and the FFS mode, no common electrode CE is disposed toa counter substrate CT, and a liquid crystal capacitance is formed inparallel with an auxiliary capacitor Cst, that is, between a pixelelectrode PE and an auxiliary capacitance line Cs (a common electrode CEdisposed to an array substrate AR).

In the case, a drive as illustrated in FIG. 16 may be used in place ofthe nH1V-CCDI drive illustrated in FIG. 2, FIG. 3, or FIG. 4. Note thata polarity pattern and a drive waveform of a display pixel PXillustrated in FIG. 16 is a case in which the 2H1V-CCDI drive isemployed.

In FIG. 2, FIG. 3, and FIG. 4, although the superimposed voltage isapplied via the auxiliary capacitance line Cs after a video signal hasbeen written to the display pixel PX, in FIG. 16, a potential of anauxiliary capacitance line Cs is changed before the video signal iswritten to the display pixel PX.

In a liquid crystal display apparatus in which a common electrode CEthat confronts via a liquid crystal layer LQ exists as in the TN mode,the OCB mode, and the like, the common electrode has the same potentialin an overall screen. In contrast, in the IPS mode, the FFS mode, andthe like, a potential of a common electrode can be changed in eachauxiliary capacitance line Cs (or a common electrode CE on an arraysubstrate AR). A drive method illustrated in FIG. 16 intends to writeboth positive and negative polarities by a small source output amplitudemaking use of changing the potential of the common electrode describedabove and can reduce a voltage amplitude or power consumption.

In the liquid crystal display apparatus in which the auxiliary capacitorCst of the display pixels PX disposed on the upper side and theauxiliary capacitor Cst of the display pixels PX disposed on the lowerside mixedly exist, a layout for making the positions of center ofgravity of the openings of the two types of the display pixels PX thesame can be applied also to the drive as illustrated FIG. 16.

Otherwise, in the liquid crystal display apparatus in which theauxiliary capacitor Cst of the display pixels PX disposed on the upperside and the auxiliary capacitor Cst of the display pixels PX disposedon the lower side mixedly exist, a layout for placing pixel openings inupper and lower symmetry can be applied also to the drive as illustratedFIG. 16.

In any of the cases, when the displays such as the 1V longitudinalstripe display or the dot-check display, and the like are executed, aliquid crystal display apparatus that avoids a defective display inwhich a lateral stripe is visually recognized and suppresses displayquality from being lowered can be provided.

What is claimed is:
 1. A liquid crystal display apparatus, comprising:an array substrate comprising a pixel electrode disposed to each ofdisplay pixels disposed in a matrix state, a gate line and an auxiliarycapacitance line extending along a row along which the pixel electrodeis arranged, a signal line extending along a column along which thepixel electrode is arranged, a semiconductor that intersects the gateline via an insulating layer and confronts the auxiliary capacitanceline, a contact electrode configured to electrically connect thesemiconductor to the pixel electrode, and a driver for driving the gateline, the signal line, and the auxiliary capacitance line; a countersubstrate disposed in confrontation with the array substrate; and aliquid crystal layer sandwiched between the array substrate and thecounter substrate, wherein, in the display pixels disposed side by sidein a direction where the gate line extends, the positions of center ofgravity of openings surrounded by the gate line, the signal line, theauxiliary capacitance line, and ends of the contact electrode are thesame in a direction where the signal line extends.
 2. The liquid crystaldisplay apparatus according to claim 1, wherein the shapes of theopenings are placed in line symmetry to the gate line.
 3. The liquidcrystal display apparatus according to claim 2, wherein each of theopenings comprises a first opening on one side of the gate line in thedirection where the signal line extends and a second opening on theother side of the gate line; the auxiliary capacitance line comprises aconvex portion projecting in the direction where the signal lineextends; the first opening being formed in a concave shape surrounded bythe gate line, the signal line, the auxiliary capacitance line, and theend of the contact electrode; and the second opening being formed in aconcave shape surrounded by the gate line, the signal line, and an endof the auxiliary capacitance line including the convex portion.
 4. Theliquid crystal display apparatus according to claim 1, wherein the drivecircuit drives a potential of the auxiliary capacitance line in eachrow.
 5. The liquid crystal display apparatus according to claim 2,wherein the drive circuit drives a potential of the auxiliarycapacitance line in each row.
 6. The liquid crystal display apparatusaccording to claim 3, wherein the drive circuit drives a potential ofthe auxiliary capacitance line in each row.
 7. The liquid crystaldisplay apparatus according to claim 1, wherein when n is an integer of1 or more, a capacitively-coupled dot inversion drive for invertingpolarity every nth row and inverting polarity every other column isemployed.
 8. The liquid crystal display apparatus according to claim 2,wherein when n is an integer of 1 or more, a capacitively-coupled dotinversion drive for inverting polarity every nth row and invertingpolarity every other column is employed.
 9. The liquid crystal displayapparatus according to claim 3, wherein when n is an integer of 1 ormore, a capacitively-coupled dot inversion drive for inverting polarityevery nth row and inverting polarity every other column is employed. 10.The liquid crystal display apparatus according to claim 4, wherein whenn is an integer of 1 or more, a capacitively-coupled dot inversion drivefor inverting polarity every nth row and inverting polarity every othercolumn is employed.
 11. The liquid crystal display apparatus accordingto claim 5, wherein when n is an integer of 1 or more, acapacitively-coupled dot inversion drive for inverting polarity everynth row and inverting polarity every other column is employed.
 12. Theliquid crystal display apparatus according to claim 6, wherein when n isan integer of 1 or more, a capacitively-coupled dot inversion drive forinverting polarity every nth row and inverting polarity every othercolumn is employed.
 13. The liquid crystal display apparatus accordingto claim 4, wherein the drive circuit changes a potential of theauxiliary capacitance line just before a video signal is written torespective pixel electrodes.
 14. The liquid crystal display apparatusaccording to claim 5, wherein the drive circuit changes a potential ofthe auxiliary capacitance line just before a video signal is written torespective pixel electrodes.
 15. The liquid crystal display apparatusaccording to claim 6, wherein the drive circuit changes a potential ofthe auxiliary capacitance line just before a video signal is written torespective pixel electrodes.